Population Genetics

Question 1

Gene pool

Answer 1

All of the alleles in a population

Question 2

Calculating genotypic frequency

Answer 2

Genotypic frequency= total # of individuals with specific genotype/ total # of individuals in population

Question 3

Calculating allelic frequency

Answer 3

Allelic frequency= # of a specific allele/ total # of all alleles

Question 4

p and q

Answer 4

p= frequency of dominant allele (B)
q= frequency of recessive allele (b)
p+q=1

Question 5

Hardy-Weinberg law

Answer 5

Method scientists use to calculate allelic and genotypic frequencies in the absence of evolutionary forces: determine genetic variation in a population

Question 6

Genetic equilibrium

Answer 6

Assumption for Hardy-Weinberg law: allelic frequencies don't change over time
No migration
Infinitely large population
Random mating
No mutation
No natural selection

Question 7

Hardy-Weinberg equation

Answer 7

p^2 + 2pq + q^2 = 1
p^2= f(AA)
2pq= f(Aa)
q^2= f(aa)

Question 8

Cline

Answer 8

Gradient for allele frequencies that changes in a systematic way according to the physical attributes of the environment

Question 9

Polymorphisms

Answer 9

Changes in DNA sequence between individuals

Question 10

How polymorphisms are found

Answer 10

Visualized by microscopy of chromosomes
Repeats are found by observing size differences between DNA sequences using gel electrophoresis
RFLP analysis to identify SNPs (single nucleotide polymorphisms)

Question 11

RFLP analysis

Answer 11

Method of identifying SNPs

SNP changes restriction enzyme site: different number of fragments observed in gel electrophoresis

Question 12

Fitness

Answer 12

Relative reproductive ability of a genotype

Question 13

Natural selection

Answer 13

Frequency of alleles that confer survival and reproduction increases in the population

Question 14

Positive assortative mating

Answer 14

Organisms mate with others that are similar to them

Question 15

Negative assortative mating

Answer 15

Organisms mate with others that are different from them

Question 16

Genetic drift

Answer 16

Changes in allele frequencies due to random sampling
Reduces genetic diversity
Ex- settlers killing off millions of bison on the Great Plains

Question 17

Bottleneck effect

Answer 17

Population is drastically reduced in number, reducing genetic diversity
Not due to anything that would reduce selectively, like certain diseases

Question 18

Founder effect

Answer 18

Population is established from a small number of breeding individuals
Reduced genetic diversity

Question 19

Immigration’s effect on alleles

Answer 19

Introduces new alleles

Question 20

Emigration’s effect on alleles

Answer 20

Takes away alleles

Question 21

Gene flow

Answer 21

An individual migrates and contributes its alleles to the gene pool of the new population